Control finger



Feb. 11, 1930. A. c. CATLIN ET AL 6,

A CONTROL FINGER Filed Aug. 6. 1925 BY zM Patented Feb. 11, 1930 UNITED STATES PATENT OFFICE ARTHUR o. cA'rLIN Ann MATTHEW J. LAMBERT, or YOUNGSTOWN, OHIO, AssIGNoEs T0 WESTINGHOUSE ELEcTEIc Ann MANUFACTURING COMPANY, A ooEroEATIoN' OF PENNSYLVANIA CONTROL FINGER Application filed August 6, 1925. Serial No. 48,690.

This invention relates, generally, to control fingers and more particularly to control fingers of the type suitable for use with drum controllers.

The object of the invention, generally stated, is the provision of a contact finger that shall be simple and efficient in operation and readily, and economically manufactured. I i r A more specific object of the invention is to facilitate the removaland replacement of the parts of a control finger subject to wear.

A further object of the invention is to provide for the limiting of the movements of the members of the contact finger to meet the conditions of operation.

Other objects of the invention will in part be obvious and in part appear hereinafter.

The invention, accordingly, is disclosed in the embodiment thereof shown in the accompanying drawing and comprises the combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of which will be indicated in the claims.

': For a fuller understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawing, in which Figure 1 is a perspective view of a contact finger constructed in accordance with this invention,

Fig. 2 is a perspective view of the contact finger showing the contact member after it has been released.

Referring now to the drawing, a shank or frame, shown generally at 10, is provided with any suitable means for attaching it to a support. In this particular embodiment of the invention, a portion of the shank is cut away forming two jaws 11 and 12 which may be made of any shape, depending on the cross section of the finger base or support on which the contact finger is to be mounted.

In order to clamp the contact finger in position on a support, such, for example, as the insulation block 18 shown in Fig. 1, a'screw 1 1 may be provided for drawing the jaws I together. As shown, the insulation block is provided with a plurality of openings 15 for the reception of fastening bolts or the like.

The forward portion of the shank 10 is cut away to provide a horizontal face for the reception of a contact member shown genorally at 16. As will be observed, the rear end of the "contact member 16 is made straight, thereby adapting it to seat upon the horizontal face that is provided on the forward end of the shank. The front end of the con tact member 16 is curved so as to present a contact portion of substantially U shape. Consequently, the contact finger will permit the movement of engaging contact members, located on a drum controller, in either direction.

In order to retain the contact member 16 in position on the base, a gripping arm 17 is provided and has two arms pivotally mounted on a pin 18 that extends transversely through the shank 10. The forward end of the gripping arm 17 is provided with a depending portion or lug 19, which is disposed to closely fit into an opening 20 that is provided in the contact member 16.

Connection between the arm 17 and the contact member 16 is maintained by a spring 21, which is mounted on a vertical post 22 that is carried by the forward end of the shank 10. It will be readily understood that the post 22 may be attached to the shank in any suitable manner, such, for example, as by providing a threaded opening in the base for the reception of a threaded end provided on the post.

As will be observed, the inner end of the contact member 16 is bifurcated so asto closely fit over the post 22. Thus, lateral movement of the contact member 16 on the base 10 is prevented because of the rigid positioning of the member 16 by means ofthe lug 19 and the post 22.

H In order to assure good electrical connection between the contact member 16 and the shank 10, a flexible connector or shunt 23v is attached to the forward end of the contact member in any suitable manner, such as riveting, as shown at 24:. Attached to the other cadet the flexible conductor .23 i a fllrminal 25 that is adapted for attachment to the shank 10 by means of a binding post 26. p

The contact member 16 may be set in different positions relative to the forward portion of the shank 10, by means of a screw 27 that is mounted in the contact member 16 and disposed to engage the shank. It will be readily understood that by adjusting the screw 27, the contact member 16 may be set at-difierent angles to the upper surface of the shank, to thus determine the lower limit of travel of the member 16. As shown, a lock nut 28 is provided to lock the screw 27 in any predetermined position. j

Manual actuation of the gripping arm 17 may be efi'e'cted in a number of ways and, in this particular construction, a fingerv piece 29 is' provided. It will be noted that the finger piece 29 extends upwardly and rearwardly to a point above the main body portion of the shank 10, where it is readily accessible to the operator. In order to permit therotation of the gripping arm 17 about its pivot point 18, by means of the finger piece 29, an elongated opening 30 is provided inthe arm for the reception of the post 22. Thus, the contact tip 16 may be quickly and easily removed and replaced without requiring any tools, except that a screw-driver only is necessary if the shunt 23 is to be removed or replaced. 7

Assume that the contact finger is used with a drum-type controller and that the contact member 16 is disposed to engage contact segments that are provided on the drum, when the latter is rotated. Then, upon a contact segment moving into engagement with the contact member 16, the latter is raised, oscillating about its point of connection (lug 19) with the gripping arm 17 and causing the bifurcated end to slide forward on the shank 10. As will be readily understood, the upward movement of the contact memberis continuously opposed by the spring 21.

The spring 21, tending continuously to force the contact member 16 to its lowermost position, assures a good electrical connection with the contact segments that are moved into engagement with it. This spring also serves to maintain the positive connection between the gripping arm 17 and the contact member 16.

It will be readily understood that as the contact member 16 oscillates about its point of connection with the gripping arm 17, the direct electrical connection between the two members is maintained only by the bifurcated end that slides on the shank. However, the flexible conductor 23, which shunts the electrical connection between the contact member 16 and the shank 10, provides for good electrical connection at all times between the two last-mentioned members.

Since various changes may be made in the above-described construct-ion and arrangement of parts and different embodiments of the invention may be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in alimiting sense.

We claim as our invention:

1. A contact finger comprising, in combination, a shank, a contact member adapted to be mounted on the shank, a gripping member positively hinged on the shank and disposed to engage the contact member to retain it in position, resilient means for maintaining the gripping arm in engagement with the contact member, a finger piece provided on the gripping member for actuating the latter to release the contact member, and means for adjusting the contact member relative to the shank.

2. A contact finger comprising, in combination, a shank, a contact member having a bifurcated end and an opening therein adapted to be mounted on the shank, a gripping arm pivotally mounted on the shank for engaging in said opening in the contact member, a pin mounted on the shank for receiving the bifurcated end of the contact member and a spring mounted on the pin for retaining the gripping arm in engagement with the contact member.

3. A contact finger comprising, in combination, a shank, a gripping arm having an opening therein hinged to the shank, a pin mounted on the shank and extending upwardly through the opening in the gripping arm, a spring mounted on the pin to bias the gripping arm to a predetermined position, and a contact member having a bifurcated end and an opening therein, said bifurcated end being adapted to engage said pin and said opening being disposed to receive the gripping arm.

In testimony whereof, we have hereunto subscribed our names this 28th day of April,

ARTHUR C. CATLIN. MATTHEW J. LAMBERT. 

